Unusually High Seebeck Coefficient Arisen from the Temperature-dependent Carrier Concentration in PbSe-AgSbSe2 Alloys

2021 ◽  
Author(s):  
Xuemei Wang ◽  
Gang Wu ◽  
Jianfeng Cai ◽  
Qiang Zhang ◽  
Junxuan Yang ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Wide Temperature Range ◽  
Induced Voltage ◽  
Temperature Dependent ◽  
Temperature Range ◽  
High Seebeck Coefficient

Seebeck coefficient describes the temperature gradient induced voltage in thermoelectrics. Usually, to obtain a high Seebeck coefficient within a wide temperature range is difficult, as it is limited by the...

Analysis of temperature dependent electrical characteristics of Au/n-GaAs/GaAs structures in a wide temperature range

Vacuum ◽  
2008 ◽  
Vol 83 (2) ◽  
pp. 276-281 ◽  
Author(s):  
A. Bengi ◽  
S. Altındal ◽  
S. Özçelik ◽  
S.T. Agaliyeva ◽  
T.S. Mammadov
Keyword(s):  
Wide Temperature Range ◽  
Electrical Characteristics ◽  
Temperature Dependent ◽  
Temperature Range

Temperature-dependent hard X-ray photoemission spectra of ternary Tl compounds with high Seebeck coefficient

2009 ◽  
Vol 6 (5) ◽  
pp. 993-996 ◽  
Author(s):  
Kojiro Mimura ◽  
Takahiko Ishizu ◽  
Kazuya Yamamoto ◽  
Junta Takasu ◽  
Yuri Yonehira ◽  
...  
Keyword(s):  
Seebeck Coefficient ◽  
Temperature Dependent ◽  
X Ray ◽  
High Seebeck Coefficient

Thermoelectric Properties of n-type (Bi2Se3)x(Bi2Te3)1-x Crystals Prepared by Zone Melting

2008 ◽  
Vol 368-372 ◽  
pp. 547-549
Author(s):  
Jun Jiang ◽  
Ya Li Li ◽  
Gao Jie Xu ◽  
Ping Cui ◽  
Li Dong Chen
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Zone Melting ◽  
Chemical Compositions ◽  
Melting Method ◽  
Temperature Range

In the present study, n-type (Bi2Se3)x(Bi2Te3)1-x crystals with various chemical compositions were fabricated by the zone melting method. Thermoelectric properties, including Seebeck coefficient (α), electrical conductivity (σ) and thermal conductivity (κ), were measured in the temperature range of 300-500 K. The influence of the variations of Bi2Te3 and Bi2Se3 content on thermoelectric properties was studied. The increase of Bi2Se3 content (x) caused an increase in carrier concentration and thus an increase of σ and a decrease of α. The maximum figure of merit (ZT = α2σT/κ) of 0.87 was obtained at about 325 K for the composition of 93%Bi2Te3-7%Bi2Se3 with doping TeI4.

The high thermopower of the Zintl compound Sr5Sn2As6 over a wide temperature range: first-principles calculations

2014 ◽  
Vol 2 (36) ◽  
pp. 15159-15167 ◽  
Author(s):  
Dong Bao Luo ◽  
Yuan Xu Wang ◽  
Yu Li Yan ◽  
Gui Yang ◽  
Jue Ming Yang
Keyword(s):  
Carrier Concentration ◽  
Wide Temperature Range ◽  
First Principles ◽  
First Principles Calculations ◽  
Temperature Range

The highest ZT value of n-type Sr5Sn2As6 at 950 K appears at a carrier concentration of 9.4 × 19 e cm−3.

Investigation of the Properties of Electrochemically Deposited Semiconductor Materials for Thermoelectric Applications

2003 ◽  
Vol 793 ◽  
Author(s):  
C.-K. Huang ◽  
J.A. Herman ◽  
N. Myung ◽  
J. R. Lim ◽  
J.-P. Fleurial
Keyword(s):  
Seebeck Coefficient ◽  
Transport Properties ◽  
Carrier Concentration ◽  
Direction Parallel ◽  
Seebeck Coefficients ◽  
Before And After ◽  
Electrochemically Deposited ◽  
High Seebeck Coefficient ◽  
Preliminary Study ◽  
P Type

ABSTRACTAt JPL, it is our desire to fabricate thermoelectric micro-devices for power generation and cooling applications using an electrochemical deposition (ECD) technique. We believe that the performance of our current micro-device developed is limited by the properties of the ECD materials. Therefore, the objective of this study is to develop ECD methods for obtaining n-type Bi2Te3 and p-type Bi2-xSbxTe3 thermoelectric materials with near bulk properties, as well as optimizing morphology and transport properties. The films of Bi2Te3 and Bi2-xSbxTe3 were initially obtained under various ECD conditions. Seebeck coefficients and transport properties were then measured along the direction parallel to the substrates before and after annealing at 250°C for 2hrs. From the data obtained, ECD n-Bi2Te3 material can achieve a high Seebeck coefficient (-189 μV/K) when it is deposited at –200 mV vs. SCE. The in-plane resistivity, in-plane mobility, and carrier concentration are 3.0 mohm-cm, 31 cm2 V−1 S−1, and 6.79 × 1019 cm−3, respectively. As for the p-type Bi2-xSbxTe3, it is possible to achieve a high Seebeck coefficient (+295 μV/K) when it is deposited at 0.3 mA/cm2. The in-plane resistivity, in-plane mobility, and carrier concentration are 9.8374 mohm-cm, 66.58 cm2 V−1 S−1, and 9.54 × 1018 cm−3, respectively. From the results of our preliminary study, we have found the conditions for depositing high quality Bi2Te3 and Bi2-xSbxTe3 materials with thermoelectric properties comparable to those of their state-of-the-art bulk samples.

scholarly journals Efficient interlayer charge release for high-performance layered thermoelectrics

2020 ◽  
Author(s):  
Hao Zhu ◽  
Zhou Li ◽  
Chenxi Zhao ◽  
Xingxing Li ◽  
Jinlong Yang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
High Performance ◽  
Lattice Thermal Conductivity ◽  
Transport Barrier ◽  
High Seebeck Coefficient ◽  
Valence Bands ◽  
Increase Carrier Concentration

Abstract Many layered superlattice materials intrinsically possess large Seebeck coefficient and low lattice thermal conductivity, but poor electrical conductivity because of the interlayer transport barrier for charges, which has become a stumbling block for achieving high thermoelectric performance. Herein, taking BiCuSeO superlattice as an example, it is demonstrated that efficient interlayer charge release can increase carrier concentration, thereby activating multiple Fermi pockets through Bi/Cu dual vacancies and Pb codoping. Experimental results reveal that the extrinsic charges, which are introduced by Pb and initially trapped in the charge-reservoir [Bi2O2]2+ sublayers, are effectively released into [Cu2Se2]2− sublayers via the channels bridged by Bi/Cu dual vacancies. This efficient interlayer charge release endows dual-vacancy- and Pb-codoped BiCuSeO with increased carrier concentration and electrical conductivity. Moreover, with increasing carrier concentration, the Fermi level is pushed down, activating multiple converged valence bands, which helps to maintain a relatively high Seebeck coefficient and yield an enhanced power factor. As a result, a high ZT value of ∼1.4 is achieved at 823 K in codoped Bi0.90Pb0.06Cu0.96SeO, which is superior to that of pristine BiCuSeO and solely doped samples. The present findings provide prospective insights into the exploration of high-performance thermoelectric materials and the underlying transport physics.

The study of structural, electronic and thermoelectric properties of Ca1−xYbxZn2Sb2 (x = 0, 0.25, 0.5, 0.75, 1) Zintl compounds

2021 ◽  
pp. 2150100
Author(s):  
I. Mili ◽  
H. Latelli ◽  
T. Ghellab ◽  
Z. Charifi ◽  
H. Baaziz ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Figure Of Merit ◽  
Narrow Gap ◽  
High Carrier Concentration ◽  
Merit Factor ◽  
Composition Formula ◽  
High Seebeck Coefficient ◽  
High Carrier

Based on the electronic structure, the physical properties of [Formula: see text] ([Formula: see text], 0.25, 0.5, 0.75, 1) Zintl compounds are studied. The transport properties can be significantly changed by varying the composition [Formula: see text]. The materials under study are more metallic with increasing [Formula: see text] and behaves like a semiconductor when [Formula: see text] decreases. It is found that [Formula: see text] exhibits a larger thermopower magnitude ([Formula: see text] at [Formula: see text] and the Seebeck coefficient decreases as [Formula: see text] increases. The calculated figure of merit factor of [Formula: see text] is found to be low, this is explained by the fact that its structure is very compact and its bandgap is small which lead to high electrical and thermal conductivity due to high carrier concentration ([Formula: see text] at [Formula: see text]). On other hand a narrow-gap (0.46 eV for [Formula: see text]), provides a balance between a high Seebeck coefficient and low electronic thermal conductivity, with a slight increase in the carrier concentration when the temperature increases ([Formula: see text] at 600 K). As a consequence, [Formula: see text] compound is predicted to have good performance for thermoelectric applications. The electrical [Formula: see text] and the thermal [Formula: see text] conductivity for [Formula: see text] compound in both directions (along [Formula: see text] and [Formula: see text]-axes) are calculated. It is obtained that [Formula: see text] is 120% of [Formula: see text] at high-temperature, whereas [Formula: see text] Seebeck coefficient was higher than [Formula: see text] especially at [Formula: see text] ([Formula: see text]. The large value of [Formula: see text] showed that the transport is dominated by zz-axis.

The Effect of A Graded in Profile on the Figure of Merit of PbTe

1998 ◽  
Vol 545 ◽  
Author(s):  
Z. Dashevsky ◽  
S. Shusterman ◽  
A. Horowitz ◽  
M. P. Dariel
Keyword(s):  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Concentration Profile ◽  
External Source ◽  
Charge Carrier Concentration ◽  
Deep Impurity ◽  
Temperature Range ◽  
Fermi Level Pinning ◽  
Type Character ◽  
Set Up

AbstractThe present study was aimed at demonstrating the possibility of producing a graded charge carrier concentration in a PbTe crystal by taking advantage of the concentration profile that is set up by the diffusion of In from an external source. Doping by indium generates deep impurity levels lying close to the edge of the conduction band. The Fermi level pinning effect and the electron population of the In impurity levels, which reduces the minority carrier concentration at elevated temperature, significantly improve the thermoelectric behavior of the resulting material. The penetration profiles of In, originating from an external gaseous or liquid source, were determined using Seebeck coefficient measurements in p- and n-type PbTe crystals. In the p-type crystal, the Seebeck coefficient changed sign as the In concentration induced a change from p-type to n-type character. The thermovoltage of a PbTe crystal in which an In concentration profile, generated by In diffiusing from a gaseous source had been established, was determined in the 50 to 430 °C temperature range. The constant Seebeck coefficient that was observed over the whole temperature range provides the experimental support for the underlying premises of this study.

scholarly journals Exceptional high Seebeck coefficient and gas-flow-induced voltage in multilayer graphene

2012 ◽  
Vol 100 (18) ◽  
pp. 183108 ◽  
Author(s):  
Xuemei Li ◽  
Jun Yin ◽  
Jianxin Zhou ◽  
Qin Wang ◽  
Wanlin Guo
Keyword(s):  
Seebeck Coefficient ◽  
Gas Flow ◽  
Multilayer Graphene ◽  
Induced Voltage ◽  
High Seebeck Coefficient

scholarly journals The Efficacy of the Interferon Alpha/Beta Response versus Arboviruses Is Temperature Dependent

mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Whitney C. Lane ◽  
Matthew D. Dunn ◽  
Christina L. Gardner ◽  
L. K. Metthew Lam ◽  
Alan M. Watson ◽  
...  
Keyword(s):  
Gene Transcription ◽  
Interferon Alpha ◽  
Wide Temperature Range ◽  
Human Disease ◽  
Therapeutic Modality ◽  
Dependent Manner ◽  
Temperature Dependent ◽  
Innate Defense ◽  
Temperature Range ◽  
Alpha Beta

ABSTRACT Interferon alpha/beta (IFN-α/β) is a critical mediator of protection against most viruses, with host survival frequently impossible in its absence. Many studies have investigated the pathways involved in the induction of IFN-α/β after virus infection and the resultant upregulation of antiviral IFN-stimulated genes (ISGs) through IFN-α/β receptor complex signaling. However, other than examining the effects of genetic deletion of induction or effector pathway components, little is known regarding the functionality of these responses in intact hosts and whether host genetic or environmental factors might influence their potency. Here, we demonstrate that the IFN-α/β response against multiple arthropod-vectored viruses, which replicate over a wide temperature range, is extremely sensitive to fluctuations in temperature, exhibiting reduced antiviral efficacy at subnormal cellular temperatures and increased efficacy at supranormal temperatures. The effect involves both IFN-α/β and ISG upregulation pathways with a major aspect of altered potency reflecting highly temperature-dependent transcription of IFN response genes that leads to altered IFN-α/β and ISG protein levels. Discordantly, signaling steps prior to transcription that were examined showed the opposite effect from gene transcription, with potentiation at low temperature and inhibition at high temperature. Finally, we demonstrate that by lowering the temperature of mice, chikungunya arbovirus replication and disease are exacerbated in an IFN-α/β-dependent manner. This finding raises the potential for use of hyperthermia as a therapeutic modality for viral infections and in other contexts such as antitumor therapy. The increased IFN-α/β efficacy at high temperatures may also reflect an innate immune-relevant aspect of the febrile response. IMPORTANCE The interferon alpha/beta (IFN-α/β) response is a first-line innate defense against arthropod-borne viruses (arboviruses). Arboviruses, such as chikungunya virus (CHIKV), can infect cells and replicate across a wide temperature range due to their replication in both mammalian/avian and arthropod hosts. Accordingly, these viruses can cause human disease in tissues regularly exposed to temperatures below the normal mammalian core temperature, 37°C. We questioned whether temperature variation could affect the efficacy of IFN-α/β responses against these viruses and help to explain some aspects of human disease manifestations. We observed that IFN-α/β efficacy was dramatically lower at subnormal temperatures and modestly enhanced at febrile temperatures, with the effects involving altered IFN-α/β response gene transcription but not IFN-α/β pathway signaling. These results provide insight into the functioning of the IFN-α/β response in vivo and suggest that temperature elevation may represent an immune-enhancing therapeutic modality for a wide variety of IFN-α/β-sensitive infections and pathologies.

Sign in / Sign up

Export Citation Format

Share Document